Methods for electronic transmission and reproduction of data in graphic form



Jan. 5, 1965 v. E. LALLY ETAL 3,164,674

METHODS FOR ELECTRONIC TRANSMISSION AND REPRODUCTION OF DATA IN GRAPHIC FORM Original Filed Oct. 22; 1956 3 Sheets-Sheet l II ///II m m WM mar w Maw A wy AB Jan. 5, 1965 v. E. LALLY ETAL 3,164,674 METHODS FOR ELECTRONIC TRANSMISSION AND REPRODUCTION OF DATA IN GRAPHIC FORM Original Filed 001,. 22, 1956 3 Sheets-Sheet 2 my QM. W W vi 4 5 mm W A Jan. 5, 1965 v. E. LALLY ETAL 3,164,574

METHODS FOR ELECTRONIC TRANSMISSION AND REPRODUCTION V OF DATA IN GRAPHIC FORM Original Filed Oct. 22, 1956 3 Sheets-Sheet 3 HRMW QW J 1 1 lllalls I I J :WEQQ NW a Q United States Patent .This is a division of application Ser. No; 617,660, filed October 22, 1956, now U.S. Patent No. 2,923,7 70,.

The invention described herein may'be manufactured and used by or for the United States Government for governmental purposes without payment to us of any royalty thereon. i

This invention relates to a method of electrographic transmission and reception of weather information and more particularly to a method in which the transmission of information is monitored and also provides for color discrimination of the information.

The present invention may be specifically applied to a Weatherplotter method vwherein weather, maps and charts are transmitted from a weather central and then received by a large number of weather stations; It may also be applied for-remote reproduction of any kind of data capable of graphic display.

In the prior art there are two basic methods for the transmission of weather dataTeletype and facsimile.

Teletype is generally utilized to transmit observational data and occasional canned analyses. "-The analyzed data and prognostic charts are transmitted over a facsimile network.

Commonly used Teletype methods provide weather data according to schedule rather than demand. Because of the enormous labor problem involved in converting map details to printable characters, the forecaster of necessitymust resort to drastic abridgments or condensations'of the available data. Furthermore, the periodic observations are often relatively obsolete by the time they are available to the forecaster. V i

The facsimile method of transmission of weather maps and charts consists primarily of the transmission of a series of lines plus various standard notations. The information content is usually not detailed since time limitations in both drawing and reading the map preclude a complicated construction. .Considered abstractly facsimile is capable of reproducing any type of graphic representation within the limits of definition provided by the number of lines per inch. However, the actual application of facsimile to reproducing awcather map involves primarily filling in the white background, and requires an inordinate amount of bandwidth. to transmit a map which consists of a series of lines. Facsimile has the following limitations for transmission of weather maps: it is too slow; charts are ordinarily too small; definition is poor on detail; geographic detail must be reduced or eliminated to prevent confusion with the isolines -of weather information; it is difficult -to write additional information on the facsimile paper; and there is'no color. contrast or other means of discrimination on a facsimile In accordance with the present invention, a weather map or-other graph is traced by viewing the signal outputof the transmitting medium and concurrently manipulating a control device, apart from the map. itself, to the proper raienressan. s, 1965 extent, and in theproper direction, to cause the application to the map of selected indices representative of weather information; the said manipulation of the control device being further effective for concurrently transmitting said signal output to remote stations.

An object of this invention, therefore, is to provide novel methods for the transmission of weather maps and charts from a weather central to a large number of remote weather stations.

A further object is to provide methods whereby weather maps and charts may be transmitted more rapidly than in existing systems. 7

Anotherobject of this invention is to provide methods of the kind described, wherein it is possible to reduce the bandwidth presently required for the transmission of weather maps and charts.

A further obj'cct'of this invention is to provide methods for the transmission and reception of weather maps and charts in a manner providing for gradations of emphasis as between successively presented bits of informational data; the emphasis dilferentiations (in the form of contrasting colors orother distinguishing aspects) being applied by means of selectively and alternately operable contrast--applying signaling circuits, under the control of the operator at the central transmitting station.

.Another object is to provide methods for the transmission and reception of weather maps and charts wherein errors may be corrected at the transmitting central.

1 The invention may be practiced by use of apparatus taking various forms. One suitable type of apparatus was disclosed in patent application No. 617,660 which issued as a U.S. patent with the Serial No. 2,923,770 of which this application is a division, and was entitled Method and Means for Electronic Transmission and Reproduction of Data in Graphic Form by Vincent E. Lally et al., and the aforementioned apparatus is. the same as is illustrated in the accompanying drawings, in which:

FIGS. 1 and 2 are, respectively, plan and profile views of apparatus suitable for practice of the invention;

FIG. 3 shows a diagram of mechanical and electronic components of the Weatherplotter Tracing Generator portion of said apparatus; and p FIG. 4 shows a similar diagram of the Weatherplotter decoder and plotting table portions of the apparatus, the latter being duplicated at each of the remote receiving stations. H

Referring now to FIG. 1, thereis shown a transmitting central for the Weatherplotter system. Map 7, inscribed with pencilled data representative of the weather information to be transmitted, is placed on top of plotting table 6. Optical viewer 9, a mirror, permits the operator of tracing generator 1 to viewthe map through the' transparent base of plotting table 6. The necessary iling X and Y mechanical positions into electrical lumination is provided by light source 8. The operator observes on the optical viewer 9 the position of the pencilled data on the completed weather map 7. This data may be in the form of lines whose directions and interrelationships will indicate component factors of a weather pattern; To transmit the selected indicia representative of weather information, the operatortraces each line bydata;it being understood that the said generator is a conventional voltage generator having co-acting movable and stationary elements whose relative. motion will cause generation of electrical current at a varyingvoltage rate;

with the voltage level'bei'ng determined by the degree of motion of the actuating handle 2L This data is utilized of the operator. I v

The-operator traces map 7 by examining the output 'of 'act as an additional obstruction. v r 7 With reference to the'signal: tracinggenerator shown in FIG. 3, the motion imparted to control device 2 by the which is represented in FIG. 4) and to actuate decoder 5.

by way of cable 11'. Decoder 5 is comprised of suitable filters and discriminators to decode the electrical data of tracing generator l and to transmit l and Y- voltages to drive the plotting table servos and to actuate the proper pen on the plotting table so as toap'ply an inked line upon map 7. ,The operator, by his constant observations of optical viewer 9, may readily see the actual position of the inked line in relationship to the pencilled line being traced. He then executes a succession oftracing apparatus by manipulating control device 2 to the proper extent, and in the proper direction to. cause the applicationto map 7 ofa succession of inked lines which Willfall precisely uponthe corresponding pencilled line-s pre-applied to said map 7. Most errors are automatically compensated between the eye and hand the system. He performsthe function of transmitting f and monitoring simultaneously. Thu s,-the operator is,

in effect, a part of a servo loop, in that'hismanipulations of control device 2 serves to compensate for many of the errors which would otherwiseexist in the system in the form of non-linearities of the transmitting circuits or gradual drifts in the frequency of the data transmission.

Calibration is automatic and no requirement exists for linearity or for stability of the frequency output of tracing generator 1. Great accuracies are possible as long as the decoders and plottingtables of the system. are selected so that their performance characteristics are essentially identical.

I While the operator is tracing and'transmitting weather map 7, by manipulating control device 2withhis right hand, he concurrently controls color selector 3 with his;

lefthand. The said color selector is comprised of three push-button self-latching switches (3, 3', 3") arranged so that pushing any one button to the-on position will control the application of one preselected color. Pen lift switch 4 is located on the side of tracing generator 1 in such a fashion that it can be reached by the left hand of the operator regardless of the position of his right hand on control device 2. Pen lift switch 4 isa push button type switch which is normally"off and which will 7 spring back to'the off positon when finger pressure is;

removed. The said switch disconnects 'the contrast-applying circuits. The mechanism operated by switches 3 and .4 isdescribed-indetail hreinafter. Y

FIG. 2 shows optical viewer 9,a mirror, which permits the operator to obtain a virtual image oif'weather map 7. By adjustment of the said. mirror, the size of the image may be varied. I The operator can trace the said map without any mechanical obstructions. Tracing speed will be faster, also, since the operators hand will not Each. button switch and itsrespe'ctive contrast-applying circuit The output of tracing generator 1 is fed to decoder 5 oscillators 53 and 54 a pair of signal patterns. whose relative frequencies will differ, one from the other, in accordance with the differences in the X and Y components of the motion resolved in linkage 31-38, which components are reflected in the correspondingly difierent tuning adjustments imparted to units 51 and 52.

'In this embodiment, the tracing generator output is within the frequency limits of 400 to 248C cycles per second. The X and Y carriers frequencies are 1700 taps. and 960 c.ps., respectively. These carriers are modulated percent. Since the change in frequency of the X and Y signals will be relatively slow when varied manually, the bandwidth required foreach channel of transmission of the significant frequency spectrum will as shown in FlG. 3 is provided with signal oscillators till and ihZ'as shown at C. During periods of transmission, oscillators 101 and N2 are continuously generating two fixed frequencies differing from each other, for example,

. 450 c.p.s. and 550 c.p.s. respectively.

The said switches are so arranged mechanically and elec- The frequencies to be transmitted are chosen by the operator by actuating color selector D which is comprised of three push button switches'ltlii, res and 167.

trically that pushing down one of-said, buttons will engage it mechanically, in addition thereto the associated switch will. make electrical contact simultaneously, the

7 previously on button will disengage and disconnect the referred to as'color tones.

electrical j contact by' means of its associated switch. Switches res and 197 will connect respectively oscillators N1 and M2. Switch 163 will simultaneously connect oscillators fill and E62. There is provided by the'above combination of oscillators TM, 102 and color selector D means whereby any one of three different frequencies may be selected for'transmission. The said frequencies are In this embodiment, oscillators'ltll, Hi2 generae green and red color tones respectively. When both outputs'of oscillators ltll and Th2 are used simultaneously a black color tone is generated. Switch ltle'normally is in the off position, when the operator presses on the said switch the circuit is closed and preselected color tone may thenbe transmitted.

The FM- outputs of oscillators 53, 54 and the color tones of oscillators ltlLltlZ are fed into isolating amplitiers til through 64,-respectively. The said frequencies are then fed into a common mixer which is comprised of resistors and capacitors 66 through 84. The output of the said mixer is then fed into amplifier 87. Output terminals 88 and 39 are adapted to feed wire lines" Out- 7 put terminals 9% and M are adapted to feed a radio transmitter to serve as part of a radio link if radio transmission and reception is desired. Lines 92 and 93 conduct This is essentially abandpass filter whose output is down operator is resolvedinto its orthogonal, or vectorial,;j

components by a conventional form of mechanical resolution-linkage indicated at 31 to 38, inclusive, which linkage includes pinions 34a" and SSwme'chaniCally as-,'

sociated; with the movable portions of capacitance plate assemblies constituting'parts of oscillator tuning units 51 and 52, respectively." in this fashion, there is set up in 6 db at 400 c.p.s., 0 db at lOQO c.p.s., and 4 db at 2600 -c. p.s. and whose input and output impedance is 600 ohms.

The output. of said simulator is taken from terminals 95 and 96' and is fed to local decoder at the transmitting station as shown in FIG. 1; I V

The receiving apparatusi of FIG. 4 isemployed at the transmitting central and at each of theremote receiving stations The input to said receiving apparatus may be the output of the tracing generator applied either directly,

through 'wire lines or fromrajdio circuits. This input consists of the. and Yi carriers with their'modulation plus C.W. color tones.

The. said receiving apparatus is comprised of limiterarnplifier 114, decoder E, and plotting table F. Limiteramplifier 114 is provided with input terminals 1'12 and 113'. :Lines 115 and 16 feed thoutput of the said amplifier-limiterto four signal pass-bandfilters 117, 113, 123

and 124 which are connected inparallel. Filters 117 and 118 separate and pass the X and Y modulated carriers and feed their associated X and Y frequency discriminators 119 and 120. Pass-band filters 123 and 124 separate and pass only the CW. green and red color tones respectively. Associated with filter 123 is multiple pole relay 125, and with filter 124 is multiple pole relay 126. During periods of transmission where color tones are absent, the contacts in relay 125 are at positions 127 and 128; for relay 126 the position is at 129.

Plotting table apparatus F is comprised of map holder 143, writing head 144, X axis positional servo 121 and Y axis positional servo 122.

Writing head 144 is physically located at 142 on map holder 143. The said writing head is comprised of three pen arms which are selectively lowered to the map surface by appropriate energization of relays 125 and 126, and electromagnets 139, 140, 141. The said pens are mounted on arm 148 serving as a holder and are lifted off the map during the absence of color tones since electromagnet 138 is energized by way of circuit connections 128 and 129 during this period and thereby holds the said arm 148 upward in the pen disengaging position.

When a green color tone is present, multiple pole relay 125 is energized and contact is made at position 145; thereby electromagnet 138 loses its energization and simultaneously, contact is made at positions 145, 146 and electromagnet 139 is energized thereby lowering the associated green pen arm so that its pen touches the surface of the map.

Where a red color tone is present, multiple pole relay 126 is energized. Connection is then made at position 147, thereupon energization is removed from electromagnet 138 and is supplied to 140 instead. The associated red pen arm is then lowered so that its pen touches the surface of the map to be traced. During periods when green and red color tones exist, both multiple pole relays 125 and 126 are energized. Connections are then established at positions 145, 146 and 147. Energization is removed from electromagnet 138 and is provided instead to 141, thereby lowering the associated black pen arm so that its pen touches the map surface. By the use of two color filters 123 and 124 in addition to multiple pole relays 125 and 126, it is possible in this embodiment to obtain three color combinations.

Two frequency discriminators 119 and 120, respectively, demodulate the X and Y carriers and provide a DC. output to plotting table servos 121 and 122. X axis positional servo 121 thus receives a DC. voltage which moves writing head 144 along the X axis in response to the X axis voltage input from decoder E. Similarly, Y axis positional servo will move writing head 144 along the Y axis in response to the Y axis lated tones which are reconverted into D.C. voltages by discriminator circuits 119 and 120 of decoder E in order to operate servo amplifiers 121 and 122 of plotting table F in such a manner as to cause a preselected color pen to follow the position of said control device 2.

What is claimed is:

1. The method of transmitting meteorological data to one or more remote receiving stations for reproduction thereat, which comprises the steps of (a) causing an image of a geographical map with meteorological data inscribed thereon to be displayed at a position displaced from said map, (b) initiating mechanical motions in accordance with visual observations made by an observer reading the meteorological inscriptions on said image map, (0) converting said motions into electrical signals, (d) utilizing said electrical signals to produce visible traces in superimposed relationship to said meteorological inscriptions and simultaneously transmitting said electrical signals to remote receiving stations for conversion into duplicate mechanical motions for transcription of said meteorological data on duplicates of said geographical map.

2. The method defined in claim 1 including the further step of creating additional electrical signals as desired, to represent colors to be applied to selected portions of the transcribed data.

3. The method as defined in claim 1 including the further step of correcting system errors simultaneously with the step of transmitting meteorological data to one or more remote receiving stations for reproduction thereat.

4. The method defined in claim 1 including the further step of creating additional electrical signals, as desired, to produce diverse markings to be associated with selected portions of the transcribed data.

5. The method of transmitting meteorological data to one or more remote receiving stations for reproduction thereat. said meteorological data being inscribed upon a geographical map, comprising initiating mechanical motions which correspond to the meteorological inscriptions on said map, converting said motions into representative electrical signals, re-converting said representative electrical signals to visible traces in superimposed relationship to said meteorological inscriptions and simultaneously transmitting said representative electrical signals to remote receiving stations for conversion into duplicate mechanical motions for transcription of said meteorological data on duplicates of said geographical map. 7 6.'The method defined in claim 5 including the further step of creating additional electrical signals, as desired, to represent colors to be applied to selected portions of the transcribed data.

No references cited.

ROBERT H. ROSE, Primary Examiner.

STEPHEN W. CAPELLI, NEWTON N. LOVEWELL,

' Examiners. 

1. THE METHOD OF TRANSMITTING METEOROLOGICAL DATA TO ONE OR MORE REMOTE RECEIVING STATIONS FOR REPRODUCTION THEREAT, WHICH COMPRISES THE STEPS OF (A) CAUSING AN IMAGE OF A GEOGRAPHICAL MAP WITH METEOROLOGICAL DATA INSCRIBED THEREON TO BE DISPLAYED AT A POSITION DISPLACED FROM SAID MAP, (B) INITIATING MECHANICAL MOTIONS IN ACCORDANCE WITH VISUAL OBSERVATIONS MADE BY AN OBSERVER READING THE METEOROLOGICAL INSCRIPTIONS ON SAID IMAGE MAP, (C) CONVERTING SAID MOTIONS INTO ELECTRICAL SIGNALS, (D) UTILIZING SAID ELECTRICAL SIGNALS TO PRODUCE VISIBLE TRACES IN SUPERIMPOSED RELATIONSHIP TO SAID METEOROLOGICAL INSCRIPTIONS AND SIMULTANEOUSLY TRANSMITTING SAID ELECTRICAL SIGNALS TO REMOTE RECEIVING STATIONS FOR CONVERSION IN- 